Such an arrangement is known to the art from, for example, Swedish Patent Specification SE No. 7905478-9. This earlier Patent Specification describes and illustrates an anti-tank mine which incorporates an initiator for initiating detonation of the mine, and a timing circuit which subsequent to a given time delay from the time of arming the mine, for example a time delay of 30-40 days, neutralizes the mine, if the mine has not been detonated prior thereto. The mine incorporates a spotter charge which is detonated in response to the act of neutralizing the mine and fires a spotter to the surface of the ground in which the mine is buried, therewith to indicate the location of the neutralized mine, the spotter being connected to the mine by means of a connecting line. The mine can then be dug from the ground and reactivated.
It is difficult, however, to dimension satisfactorily the force at which the spotter is propelled. For example, if this force is dimensioned so as also to resist hard earth layers, so that the spotter is reliably driven to the surface of the ground, the speed at which the spotter moves may be excessively high in the case of lightly of loosely packed earth layers, such as to cause the connecting line to break and the spotter to disappear, thereby making it difficult to locate the mine. If, on the other hand the mine is dimensioned for a lighter driving force, the speed at which the spotter is propelled through the ground may be too low, for example in the case of hard earth layers, for the spotter to penetrate to ground level.